Primer valve



April 18, 1939. v. c. BOYDSTON 2,154,659

PR I MER VALVE Filed 001;. 8, 1938 INVENTOR.

Patented Apr. 18, 1939 UNITED STATES PATENT OFFICE Application October 8,

4 Claims.

My invention relates to automatic primer valves and more especially to automatic valves as used for the purpose of supplying or diverting a very small proportion of the water passing through a main or branch supply pipe for the purpose of maintaining the level of water seal in the trap of a floor drain.

Floor drains and other drains connected to a sewer are commonly provided with a trap dea; signed to provide a water seal against the return of sewer gas. The preventive value of such a trap depends upon the maintenance of the water level in the trap. This seal water may be lost by evaporation, when the drain has not been used ii for a period of time; or the seal water may be syphoned out by a developed fault in the building sewage and vent system.

The objects of my invention are,

To provide a valve having a comparatively large, valved discharge aperture which will not be easily stopped up by debris or sediment as might be the case in a valve in which the discharge aperture was made very small or restricted by other means in order to provide a small discharge of water;

To provide a valve which, upon operating to discharge water to a trap by reason of water usage through its main passage, will open its discharge valve widely and then close the same positively after a short time interval regardless of the length of time that water is being used;

To provide a valve having the foregoing features and in which also the duration of opening of the discharge valve will be inversely proportional to 35 the supply pressure so that the amount of water discharged to the trap will be practically independent of the supply pressure;

To provide a valve which will operate to discharge water to a trap upon the first usage of water from a pipe served through the valve, but which will remain inoperative to subsequent usage until after a given time has elapsed after the cessation of use, thereby conserving water which would be unnecessarily discharged by a valve which is operative to every usage;

To combine in a valve as described above a minimum of simple, rugged parts as will not easily wear or get out of adjustment.

I accomplish the foregoing by means of the construction and principles described below and which are illustrated in the accompanying drawing, in which- Fig. 1 is a sectional elevation of the valve taken on the longitudinal center-line,

Fig. 2 is a side elevation, and

1938, Serial No. 233,981

Fig. 3 is a section taken along the line 3--3 of Fig. l.

A valve body I0, of hollow cylindrical form, has its upper portion smoothly bored as a cylinder M to accommodate a piston l3 slidable vertically 5 therein. The upper end of said body is closed by a pressure tight, screw-threaded cap 25. An inlet connection and an outlet connection l2, integral with said body, are screw-threaded to ac-- commodate pipe conduits and open into the cyl- 1o inder M. A portion of the wall of the cylinder l4 7 extends downwardly into the inlet II, as indicated at I la, and a like portion l2a extends upwardly into the outlet I2. The foregoing arrangement constitutes an offset passage through said cylinder and causes the piston I3 to be forced upward within said cylinder upon the passage of liquid therethrough.

A by-pass port 2|, in the form of a groove formed in the wall of the cylinder l4, extends downwardly from a point above the highest point of travel of the piston l3 and merges into the outlet [2 and thereby provides an outlet for liquid from the blind upper end of said cylinder so that said piston will not be blocked in its upward travel.

That portion of the body H3 below the inlet l l and outlet I2 is bored to a smaller diameter than the cylinder 14, opens into said cylinder and is closed at its lower end by a partition 23 to form a cylinderZZ. The partition 23 is formed with an inwardly raised, circular, concentric boss which is pierced axially with an aperture [8 to form a discharge valve seat 24.

It is not essential to the operation of the device that the lower cylinder 22 be of lesser diameter of bore than the upper cylinder id. One continuous cylinder of uniform bore would suffice, providing that the parts were correspondingly proportioned. In the practical construction of such a valve, the cylinder It is made of such a diameter that the area of the transverse passage from the inlet H to the outlet 52 through the said cylinder will be greater than the area of the supply pipe, thus minimizing the friction loss. Were this diameter of cylinder continued downwardly to the discharge valve seat 24, it would result in unnecessarily large and cumbersome construction.

The extreme lower end of the body It! is open downwardly and is screw-threaded at 25 to accomm'odate a pipe conduit to conduct the discharge to a drain trap. The barrel portion of said body between the outlet 25 and the partition 23 is provided with opposite openings 26 and 21,

preferably in line, to make visible the flow of liquids from the aperture I8 and also to admit air and thus preclude the possibility of back-syphoning of liquid from the drain trap, should such syphoning tend to occur when the supply line is drained.

The piston 13 is concentrically hollow bored and open at its lower end to form a dash-pot cylinder to accommodate a piston I 5a formed at the upper end of a valve member I5. Said valve member comprises the piston I5a, a stem of smaller diameter, a circular flanged portion I5b, adjacent the lower end, and a recess I5c at its lower end to receive a composition valve disc I! co-operating with the valve seat 24. The diameter of the flange l5b, with reference to the bore of the cylinder 22, is such that the annular space between the said parts has an area equal to or slightly greater than the area of the aperture I8.

The upper end of the valve member I5 is guided centrally by the co-operation of the piston portion I5a with the bore of the piston I3 and the lower end is similarly guided by the flange portion I5b in cylinder 22, so that said valve member may travel vertically in said cylinder and the valve disc II will register with the valve seat 24 when said valve is at the lowest point of its travel.

The proportions of the respective lengths of the cylinder 22, the cylinder I4, the piston I3 and the valve member I 5 and its piston l5a must be such that when the said valve member is in its normally closed position and the piston I3 is at its highest point of travel, the piston I5a will be engaged with the bore of piston I3. Likewise, when both members are in the position of extreme upward travel, the flange portion I5b will be within the bore of the cylinder 22.

With the valve connected with the inlet II to a source of water under presure, the outlet I2 to a faucet or other water-consuming device and the discharge connection 25 through a gravity pipe line to a trap, and with no water flowing through the valve, the piston I3 and the valve member I5 will be held by gravity in their respective lower positions and the water pressure will press the valve disc I1 against the seat 24 so that no water will discharge from the aperture I8. When a faucet in the line of the outlet I2 is opened, the pressure on the discharge side of the piston I3 is reduced below that of the inlet side and water entering the cylinder I4 below said piston will force it upward so that water may flow through the valve. Upon the initial upward movement of the piston I3, the valve member I5 will be drawn upward with said piston by the suction of the piston I5a in the bore of the piston I3, opening the discharge aperture, and water will flow through the cylinder 22, past the flange I52) and out said aperture I8, into the pipe line to the trap.

Owing to the restriction to flow through the cylinder 22, offered by the narrow annulus around the flange I 51), the pressure above said flange will be greater than that below it and a downward force will be exerted tending to withdraw the piston I5a from the bore of the piston I3. If water continues to flow through the valve from outlet I2 and the piston I3 is thereby held in its raised position, the valve member I 5 will descend slowly by reason of the force previously mentioned to close the discharge from the aperture I8. If the faucet should be closed immediately after opening, both members, the piston I3 and the valve I5 will rise and descend without change of position relative to each other.

The length of time during which the valve I5 will remain in open position is determined by the closeness of fit between the piston I51: and the bore of the piston I3, the clearance between the flange I5b and the cylinder 22 and also by the supply pressure. Closer fit of the first mentioned will increase the time; closer fit of the second will decrease the time; and higher supply pressure will decrease the time. factors are determined in the manufacture of the valve and are so proportioned as to allow a discharge time to the trap of from one-half to one second at a pressure of forty pounds per square inch.

When the faucet is closed, the pressure throughout the valve is equalized and gravity will tend to force the piston l3 downward. The water in the bore of the piston I3 above the piston I5a must flow out past that piston I5a and the water in the lower end of the cylinder I I below the piston I3 must be displaced to the upper end of said cylinder as the piston I3 descends. The clearances between the above mentioned parts are designed so that it will require from one to two minutes for the piston I3 to travel from its raised position to its lower position after water has ceased to flow through the valve.

It may be seen that, due to the length of time required for the piston I3 to descend from its raised position, if water is drawn intermittently from a faucet and at close intervals, as is frequently 'the case, the Valve will function to void water to the trap only upon the initial opening of a faucet for such use and will not have descended far enough to lift the valve I5 if such subsequent openings of the faucet are closely following. It is also evident that the amount of water voided to the trap per operation of the valve will be almost independent of the supply pressure because if the pressure is high and, consequently, the quantity per second flow through the aperture I8 is high, the time of opening of the valve will be short due to the greater force acting to close the valve. Conversely, with a low water pressure, decreased velocity of flow and longer time will result in an approximately equal amount of water discharged.

The arrangement of the partition portions Ila and I2a and the reduced diameter of the stem portion of the valve member I5 are such that very little obstruction to the direct flow of water The first two through the valve is ofiered, with consequently very low pressure drop.

It is understood that I have illustrated one of the simple embodiments of the principles of my invention for the purpose of describing the same and that variations in form and construction may be made as will lie within the following claims.

Having thus fully described my invention, the manner of its use and the advantages due to its use, what I claim as new and desire to secure by Letters Patent, is:

1. In a primer valve, having an inlet and an outlet connection, valve means for discharging water to a trap and means for opening said valve upon the passage of water through said inlet and outlet, a dash-pot connecting means between said valve and said opening means.

2. In combination in a primer valve, a body having main inlet and outlet connections, a cylinder interposed and communicating therewith, said cylinder having a closed upper end and a valved outlet at its lower end, a piston adapted to slide within said cylinder, said piston normally obscuring said main outlet and opening same upon the passage of liquid therethrough, a valve co-operating with said valved outlet to normally close the same, and a dash-pot connection between said piston and said valve.

3. In combination in a primer valve, a body having a main inlet and outlet connection, a cylinder interposed having a closed upper end and a valved outlet at its lower end, said cylinder communicating with said inlet and outlet connections, a piston adapted to slide within said cylinder, normally obscuring said outlet and opening same upon the passage of liquid therethrough, a valve for said lower outlet having a flanged enlargement thereof, loosely fitting the same upon the passage of liquid therethrough, a

valve for said lower outlet having a flanged enlargement thereof, loosely fitting the bore of said cylinder, dash-pot connecting means between said piston and said valve, and a by-pass connecting the closed upper end of said cylinder with 15 said main outlet.

VERNE C. BOYDSTON. 

